Antman, powder coating is easy, and I'm surprised you haven't done it yourself. You can get a used oven and a powder coat gun for less than the cost of 2 wheels. Powder will depend on the source, but you can find some bulk virgin powder pretty cheap, usually.
Preheat the over to 400 deg.
Thoroughly clean the surface.
Attach lead as required.
Apply powder with the gun.
Carefully move the rim into the oven.
Drink beers for 20-22 mins.
Drink more beers and take the rim out to cool or let it cool in the oven.
Rinse and repeat for all of the rims.
Turn off oven.
I almost set up a larger scale setup myself, but decided not to powder coat the trail wheels I have. If I do, I'll follow the steps above.